Hosain Rahman’s Jawbone may have first made a name for itself because of its line of high-performance Bluetooth headsets, but these days it has taken on a healthier image thanks to its more recent forays into activity tracking with the UP wristband.

As it turns out, Jawbone is far from done tinkering with the UP experience. According to a new report from GigaOM, Jawbone has acquired San Francisco startup Massive Health and Portland-based design firm Visere to help out. Sources with knowledge of the deal have told TechCrunch that the transaction for Massive Health was a talent acquisition, but also that stock and money changed hands totaling in the millions.

Massive Health was founded in 2010 by Sutha Kamal and former Mozilla creative lead Aza Raskin with the goal of using data and smart, intuitive design to reinvent how people grapple with, well, their health. The startup locked up $2.25 million in funding from Andreessen Horowitz, Charles River Ventures, and others back in February 2011, and is perhaps best known for its nutrition-conscious Eatery app. The app managed to pick up some considerable early traction — users logged more than 7 million food ratings in Eatery’s first five months on the market, but CEO Kamal wound up leaving Massive Health less than a year later.

Speaking of Eatery, it’s essentially stuck in limbo. According to a post on Massive Health’s website, Jawbone will continue to maintain the app for the time being, but it already seems as though active development has stopped — the app’s update was pushed out nearly one year ago.

Visere isn’t as prominent a party as Massive Health, but it’s no less important and the company isn’t exactly a stranger to the Jawbone team. The Oregonian design firm had a hand in crafting the Jawbone UP’s companion iOS app, and it seems that talks of an acquisition have been in the works since at least July (or so this blog post from former Visere technology director Adam Wulf indicates).

Curiously, former Visere UX lead Dayn Wilberding also notes on his personal site that Jawbone had already acquired Visere, and made the transition to his new employer in April 2012. Bringing a team that already had a hand in shaping the Jawbone UP app’s design language is certainly a logical move, but it may not be as new as it seems at first glance. According to GigaOM founder Om Malik, the two transactions have yielded a total of about 25 people that will be (or in some cases, have already been) folded into Jawbone’s software and design teams, though I imagine it’ll be some time before the fruits of this newly unified team become known to the rest of us.